Stud screw wrench



June 9, 1936. F, WEGNER 2,043,274

STUD SCREW WRENCH Filed 001;. 1a, 1934 INVENTOR FRED C. WEGNER I ATTORNEY thereof.

Patented June 9, 193 6 UNITE .FFHQE.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates to a stud screw wrench and has for an object to provide an improved tool for driving and extracting stud screws.

Stud screws, as is well known, are threaded male elements having no definite head for receiving an operating tool. They are used in many places. For example, in securing the cylinder head to an engine block, a plurality of stud screws are inserted in the engine block and intended to project through suitably provided apertures in the cylinder head and then securing nuts are placed on the ends of the stud screws on the outside of the cylinder head. In this use, as in many other uses, it is often necessary to remove and replace one or more stud screws from the engine block. Previously this was generally done bythe use of a Stillson or pipe wrench placed about the stud screw, generally below the outer threads This method is not applicable should the threads extend the entire length of the stud screw as it tends to mar the threads. Even when there is an unthreaded portion on the stud screw, however, this previous method is undesirable because the body of the male member is generally scratched and marred and will not fit easily and smoothly through the aperture provided in the cylinder head.

With this invention it is possible to 'drive'or to remove the stud screw-from the engine block without marringleither the body or the threads of the stud screw. It is possible "to easily and quickly place this tool into operative position and then, once it is inoperative position, to secure a positive grip on the stud screw for either securing the screw firmly in the engine block or for removing the stud screw from the engine block, no matter how firmly it is already secured therein.

Other objects, novel features, and advantages of this invention will be apparent from the following specification and drawing, wherein:

Fig. 1 is a top plan view of the assembled tool;

Fig. 2 is a bottom plan View;

Fig. 3 is a top plan View of the body;

Fig. 4 is a sectional view on line 44, Fig. 1;

Fig. 5 is a bottom. plan view of the sleeve; and

Fig. 6 is an elevational view of the locking spring.

There is shown at II] the assembled stud tool or wrench which includes a body ll, sleeve I2, and locking spring I3. Body II, as shown, is hexagonal in outline so as to allow an ordinary nut wrench to be applied thereto for operating the tool although it will be understood that instead, if desired, a handle may be integrally attached to the body I I. The body I I is provided with an internal aperture extending therethrough, this aperture being divided into a plurality of cammed surfaces I l. Four of these cammed surfaces M are shown but more or less may be employed, as desired. The sleeve I2 is internally threaded as at it, these threads l5 being adapted to cooperate with the male threads of the stud 'screw. The sleeve is divided by a plurality of longitudinal slots is extending as far as adjoining flange H. The slots I6 divide the sleeve into a plurality of sections 58, the external surfaces of which are cammed as at I9, the cam l9 being of a size and shape to cooperate with the internal cam i l in the body H. The flange ii is provided with a locking pin groove 28 adapted to cooperate with the locking pin 2i extending from the surface of the body II.

To assemble the. tool the sleeve I2 is inserted through the aperture in the body 9 I, the cammed surfaces it of the sleeve coming within the cammed surfaces i l in the body II. After the sleeve it has been inserted in the body II, the locking spring I3 is placed in an appropriately formed slot 22 in the other end of the sleeve sections I3 so as to hold the. sleeve from falling out of the body I I. It will be observed, however, that when in operative position the spring 22 and flange l'l allow the sleeve l3 and body I I to have relative longitudinal movement to each other a distance at least equal to the length of the locking pin 2i so that the pin may be placed within the groove 20 or may be removed therefrom while the sleeve and body are held in .assembled position.

To operate this invention the body and sleeve are moved longitudinally relative to each other so as to bring the pin 2| within its groove 20, thereby preventing relative rotation between the sleeve and the body. While being held in this position any ordinary wrench is applied to the outside of the body Ii] and it may be threadedon to the stud screw in the same manner as any ordinary nut, the pin 2! and groove 28 causing the sleeve I2 to partake of the rotation of the body I i. When the tool has been threaded onto the stud screw a suiiicient distance, the body II is then displaced longitudinally to allow the locking pin 2| to be displaced from its groove 23. Then, as for driving the stud into the engine block; the rotation of the body H is continued by means of the operating tool. The body Ii commences to rotate relative to the sleeve I2 bringing the cammed surfaces Id of the body Ii against the cammed surfaces I9 of the sleeve portions I8, tending to squeeze the sleeve portions toward each other tightly on the stud screw until ultimately the sleeve portions are locked firmly against the threads of the stud screw and the sleeve and stud screw partake of the rotation of the body II.

To remove the tool, the body I! is merely reversed in its rotation releasing the cammed surfaces from pressure against each other and allowing the tool to be removed from the screw. To remove the stud screw from the engine block, the assembly is placed on the screw in a reversed position so that when the pin 2| is removed from its groove 20 the cammed surfaces l4 and It will operate in a reverse direction and cause the sleeve to be tightened about the stud screw in an extracting instead of a driving direction.

The invention described herein may be manufacture and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded cylinder sleeve member adapted to extend through said internally aperture body member, and cooperating external eccentric cammed surfaces on said sleeve member and internal eccentric cammed surfaces on said body member, said surfaces being parallel to the axis of said cylindrical sleeve.

2. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded sleeve member adapted to extend through said internally aperture body member, cooperating external eccentric cammed surfaces on said sleeve member and internal eccentric cammed surfaces on said body member, and means for locking said sleeve member and body member against relative rotation preventing cooperation of said cammed surfaces permitting said sleeve and body members to be moved as a unit.

3. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded sleeve member adapted to extend through said internally apertured body member, cooperating ex ternal cammed surfaces on said sleeve member and internal cammed surfaces on said body member, and means for locking said sleeve member and body member against relative rotation preventing cooperation of said cammed surfaces, said means comprising a pin on one of said members and a cooperating groove on the other of said members, said pin and groove being adapted to be displaced from operative position by slight relative longitudinal displacement of said body and sleeve.

4. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded sleeve member adapted to extend through said internally apertured body member, cooperating external eccentric cammed surfaces on said sleeve member and internal eccentric cammed surfaces on said body member, means for locking said sleeve member and body member against relative rotation preventing cooperationg of said cammed surfaces while permitting said members to be rotated as a unit, and means preventing longitudinal separation of said sleeve and said body.

5. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded sleeve member adapted to extend through said internally apertured body member, cooperating external eccentric cammed surfaces on said sleeve member and internal eccentric cammed surfaces on said body member, means for locking said sleeve member and body member against relative rotation preventing cooperation of said cammed surfaces while permitting said members to be rotated as a unit, and means preventing longitudinal separation of said sleeve and said body, said latter means comprising an externally projecting flange at one end of said sleeve and a locking spring at the other end of said sleeve.

6. A stud extracting and driving tool comprising an internally apertured body member, a longitudinally slotted internally threaded sleeve member adapted to extend through said internally apertured body member, cooperating external eccentric cammed surfaces on said sleeve member and internal eccentric cammed surfaces on said body member, means for locking said sleeve member and body member against relative rotation permitting said members to be rotated as a unit, and means preventing longitudinal separation of said sleeve and said body, said latter means comprising an externally projecting flange at one end of said sleeve and a locking spring at the other end of said sleeve, said flange integrally uniting the cammed threaded portions of said sleeve.

FRED C. WEGNER. 

